1. Technical Field
This invention relates in general to piping, and more particularly, to a seat positionable between a portion of pipe and a surrounding pipe support structure such as to cradle the pipe, isolate the pipe from the pipe support, and inhibit the collection of corrosive material on the pipe in the vicinity of the pipe support.
2. Description of the Prior Art
Pipes are made of a great variety of materials, including plastic, copper, iron, steel, and other metals. Perhaps the most extensively used pipes in industrial and commercial buildings, however, are black iron or carbon/steel pipes because of their great strength and relatively inexpensive cost. Two types of pipe support structures are in general use today for these pipes.
One type of support structure consists of a plurality of suspended hangers, each of which loosely encompasses and supports the pipe at an appropriate elevation. Supporting hangers, comprising in part strips of a few inches width, are spaced every 8 to 10 feet along the pipe, depending upon the pipe weight to be supported. The other type of support in common use consists of a bridge or frame structure, which is also constructed to maintain the pipe at a suitable elevation by providing support to the pipe at predetermined spaced intervals. Bridge or frame support structures are typically metallic in nature, frequently being constructed of steel I-beams. Inverted U-shaped bolts are affixed to each supporting, horizontal leg of the bridge or frame structure to surround the pipe and prevent appreciable lateral pipe movement. Both types of support, i.e., hangers and bridge structures, may allow pipes to slide freely axially and both may accomodate a degree of radial expansion and contraction. Axial and radial degrees of freedom are often necessary since pipes commonly expand and contract with changes in ambient conditions, such as temperature and humidity.
A principal problem with both types of pipe supports, which does not appear to have been previously addressed, involves corrosion of the pipe and/or support. Corrosion is defined as a naturally occurring physical and chemical deterioration of a material, especially metal, due to reaction with its environment. The most familiar form of corrosion is rusting, which results from oxidation of the metal. In most industrial and many commercial settings, e.g., chemical, paper and petroleum plants and large commercial buildings, there are airborne materials which either themselves corrode carbon/steel pipe (e.g., any of a wide range of acidic compounds) or facilitate, i.e., enhance, the corrosion of such pipes, through oxidation (e.g., water) (hereinafter collectively referred to as "corrosive material").
Corrosion of industrial and commercial pipes is frequently greatest at those areas contacting the support structure. This is due in part to the collection and rentention of corrosive material between a pipe and its support structure. For example, if a pipe is exposed to the elements, water from rain or snow collects on the pipe and its support, and between the pipe and its support structure. Additionally, even if a pipe is protected from the elements, ambient conditions may cause beads of water or "sweat" to form on and between the pipe and its support structure. Normally, water simply evaporates from these surfaces with time, however, because of a lack of air flow between the pipe and its support structure, moisture remains there for longer time intervals which in turn results in a higher rate of pipe and/or support structure corrosion.
Corrosion is also enhanced with the erosion of the protective covering on the pipe and/or its support structure from the abrasive contact action between the pipe and the support as the pipe undergoes normal expansion and contraction. Additionally, it is well established that corrosion of metal is typically faster along a surface where two metals contact, such as where the carbon/steel pipes contact their metallic support structures.
Over time, sufficient corrosion damage can occur in the pipe and/or its support structure, from a combination of one or more of the above factors, as to require replacement of the pipe or support structure. If unanticipated, replacement of the pipe or its support structure can be costly, disruptive and a time consuming project. Should a corroded pipe or support structure not be replaced when necessary, a dangerous situation can exist which could ultimately result in a break or explosion, causing serious personal injury and/or costly environmental damage.
Each year industry expends substantial amounts of money to maintain and protect pipes and associated pipe supports against corrosion with the application of surface coatings such as paint. Regular painting of pipes and their support structures, however, often only serves to disguise a dangerous situation by concealing the extent of corrosion, particularly at those areas where the pipe contacts its support structure.
Existing modifications to the two types of support structures described do not address the corrosion problem, and in fact only serve to worsen it. For example, the placement of a rubber or foam pad between a pipe and its support, or the provision of galvanized half sheets of metal to cradle the pipe, only serve to increase the collection and retention of corrosive material between the pipe and its support structure.
Therefore, there presenty exists a genuine need for a seat positionable between a portion of pipe and its surrounding support structure which isolates the pipe from the support and inhibits the collection of corrosive material between the pipe and its support.